If I move up a 22 year old player from AAA to ML who is an 83 overall and projected to eventually become a 92 will it stunt his growth or slow his progression at all if he plays EVERYDAY at the ML level?

Players continue to develop at any level IF they are getting playing time. Playing time is the most important factor in player development. If he'll sit on your ML bench after you call him up, that will stunt his development. But if you call him up and play him regularly, like burnsy said, he may actually develop a bit better because he'll be getting the benefit of better coaches at the ML level.